This morning I drove to Tennecape, Nova Scotia to collect some pyrolusite (manganese dioxide), an important source of manganese primarily used in the steel manufacturing process. There is an old abandoned mine, even a manganese cave in nearby Walton, however, this mineral can be easily collected along the base of the conglomerate cliff walls on Minas Basin. Here are a few pieces at the site this morning.
The pyrolusite is bluish black and leaves a dark stain on most things it comes into contact with. I process this mineral to make manganese ore loads for my hoppers and/or ore cars. Since I am switching from HO to O, I will require a bit more volume than I have in the past. First step is to wash the ore to clean off saltwater, sand, and organic debris.
Then the pieces are air-dried.
Several pieces are wrapped in disposable cloth and crushed on a rough surface. The cloth keeps pieces from flying everywhere and the rough concrete leaves many of the pieces jagged like real ore, not all pulverized into powder. Note the staining I was talking about. This is the only spot my wife lets me do this.
Open the cloth and most of the crushed ore has been contained.
Once I get eno
ugh I move on to grading.
The crushed ore is graded by using four sieves with known mesh sizes.
The sieves stack together so that the finest powder will fall through the bottom and the largest chunks stay on the top. These sieves are used to make frit in the stained glass craft.
The pieces that don’t fall through the largest mesh are nominally larger than 5.2 mm. They will be crushed again.
The pieces that are trapped by the second mesh fall in the 2.7-5.2 mm size range. They are stored in bottles for modelling applications. This is a good size for O scale ore loads.
Particles trapped by the third mesh fall into the 1.2-2.7 mm size range. This looks great in HO scale hoppers and ore cars.
Particles trapped by the fourth mesh are typically in the 0.2-1.2 mm size range. I don’t use manganese for track ballast but I do use shale for ballast using this particle size.
The powder that falls through all four sieves is typically smaller than 0.2 mm in dimensions. I use this powder as colour filler in adhesives and paints, and I use it to stain ore cars so they look like they work the manganese mines.
I don’t have any O scale ore cars or hoppers yet but here is an HO scale car carrying a load of manganese ore and stained with the manganese powder. So, that’s how I grade all of my real Nova Scotia rocks, minerals, and ores.
Pretty cool Scratch!
I used to carry some plastic bottles in the car when we traveled to Colorado/points west to collect different detritus for the layout. Also collected street dirt in the local area where it collects in parking lot/curbs. Baked it for an hour in the oven at 180-200, screened it to different sizes.
I have a gray/brown shingled composite roof. I also collect the aggregate that collects in the gutters. Perfect size O scale ballast for the dirty/yard areas.
Very cool! I guess I need to poilsh up on my geology. I always thought manganese had more of a shiny, silver like appearance. It’s one of the components in stainless steel, correct?
Now that’s old school! 
Pure manganese is silvery but never found this way in nature. When combined with other elements, oxygen for example, it can take on quite different colours. It is indeed an important alloy constituent.
Also sawdust I collected/dyed - used that and sifted blast sand as a texture base in cheap dilute latex earthtone paints before adding the scenic grass/foams from the scenery suppliers.
Home Depot and Lowes usually have mis-mixed paint cheap - and like the kids decades ago with Easter Egg dyes, the resultant mix is usually brown. Not as common now the computer makes the paint.
I do a lot of wood carving and keep all the sawdust for scenery too. I process (dye) my sawdust using the technique described by Dave Frary and Bob Hayden, “Dyeing Sawdust,” Railroad Model Craftsman, September 1973, Vol. 42(4), pp. 48-49.